Heat exchanger cleaning system and heat exchanger cleaning method

ABSTRACT

A heat exchanger cleaning system comprises: a target rotating body which rotates around a rotation axis; a first inlet through which first gas on the target rotating body is introduced; and a first soot blower located in the inner space of the first inlet and including a first injection port through which a first substance is injected and a second injection port through which a second substance is injected, wherein a first distance of the first injection port from the rotation axis is substantially the same as a second distance of the second injection port from the rotation axis. A heat exchanger cleaning method using the heat exchanger cleaning system comprises: a step for positioning the first soot blower; a step for spraying the first substance and the second substance at the same time; and a step for removing foreign substances.

TECHNICAL FIELD

The present invention relates to a heat exchanger cleaning system and aheat exchanger cleaning method, and more particularly, to a heatexchanger cleaning system with improved cleaning efficiency of a targetrotating body, which is a component of a heat exchanger, as well as aheat exchanger cleaning method.

BACKGROUND ART

Nitrogen oxides (NO_(x)) are included in exhaust gas discharged fromcombustion engines such as boilers, and these nitrogen oxides causepollution so that these need to be removed before being discharged intothe atmosphere. As a method for removing nitrogen oxides contained inexhaust gas, selective catalytic reduction (SCR) is mainly used.Meanwhile, when the exhaust gas passes through an SCR device, aconcentration of sulfur trioxide in the exhaust gas increases, andammonia (NH₃) used in the catalytic reaction of the SCR device may reactwith sulfur trioxide and moisture (H₂O) included in the exhaust gas toform ammonium hydrogen sulfate (NH₄HSO₄)—also called ammonium bisulfate.When the heat exchanger (gas-air heater (GAH) or gas-gas heater (GGH))installed at the rear of the SCR device is operated continuously for along time, foreign substances (reactants) including ammonium hydrogensulfate would be accumulated in the heat exchanger, hence causing aproblem of deteriorating ventilation in the heat exchanger.

In order to solve this problem, a heat exchanger cleaning device (sootblower) may be installed in the upper and/or lower part of the heatexchanger so as to remove foreign substances accumulated in the heatexchanger.

Conventionally, a method of removing foreign substances by injectinghigh-temperature steam or high-pressure water into the heat exchangerhas been used. However, when high-pressure water is injected, theconcentration of moisture in the exhaust gas increases and causes aproblem of deteriorating the performance and lifespan of a deviceinstalled at the rear end of the heat exchanger (for example, a dustcollector). Therefore, it is necessary to separately provide a devicefor recovering a large amount of wastewater generated due to the abovemethod.

Korean Patent Registration No. 10-1555227 (Patent Document 1) disclosesa dry cleaning method using dry ice pellets instead of sprayinghigh-pressure water. This method is effective when only ammoniumhydrogen sulfate is present as a foreign substance, but it is difficultto remove foreign substances comprising a combination of differentcomponents due to deterioration in fuel quality, etc. Specifically, whenthe foreign substance is frozen due to low atmospheric temperature,there is a problem that foreign substances cannot be effectively removedby only the above cleaning method.

Korean Patent Registration No. 10-1387024 (Patent Document 2) disclosesa method of removing foreign substances from the inside of the heatexchanger by injecting hot steam and dry ice pellets inside the heatexchanger. According to this method, high-temperature steam and dry icepellets are injected in a flow direction of air supply and/or exhaustgas from a cleaning device disposed on the inlet side of the heatexchanger. However, since the temperature at the inlet of the heatexchanger into which the exhaust gas flows is high, a sublimation speedof the dry ice pellets may be accelerated and therefore cleaning effectsmay be reduced. If the high-temperature steam injected from the cleaningdevice disposed at the inlet of the heat exchanger into which thesupplied air is introduced into the boiler, damage to the boiler mayoccur and thermal efficiency of the boiler may also be reduced. Inaddition, even if hot steam and dry ice pellets are sprayed, the targetis still rotating and a cleaner is also moving, hence causing a problemthat cleaning effects at a specific target point may be deteriorated.

(Patent Document 1) KR10-1555227 B

(Patent Document 2) KR10-1387024 B

DISCLOSURE Technical Problem

An object of the present invention is to provide a heat exchangercleaning system with improved cleaning efficiency of a target rotatingbody (“target rotor”), which is a component of a heat exchanger, as wellas a heat exchanger cleaning method.

Technical Solution

The heat exchanger cleaning system according to an embodiment of thepresent invention may include: a target rotor that rotates around avirtual rotation axis extending in one direction; a first inletpositioned above the target rotor; a first outlet positioned below thetarget rotor and opposed to the first inlet; a second inlet positionedbelow the target rotor and spaced apart from the first outlet; a secondoutlet positioned above the target rotor and opposed to the secondinlet; and a first soot blower positioned in an inner space of the firstinlet.

The first inlet may be a passage through which a first gas is introducedtoward the target rotor. The first outlet may be a passage through whichthe first gas passing through the target rotor is discharged. The secondinlet may be a passage through which a second gas having a temperaturelower than that of the first gas is introduced toward the target rotor.The second outlet may be a passage through which the second gas passingthrough the target rotor is discharged.

The first soot blower may include a first nozzle through which a firstmaterial is injected toward the target rotor, and a second nozzlethrough which a second material is injected toward the target rotor. Thesecond nozzle may be positioned at a predetermined interval from thefirst nozzle.

A first distance of the first nozzle spaced apart from the virtualrotation axis of the target rotor may be substantially the same as asecond distance of the second nozzle spaced apart from the virtualrotation axis of the target rotor.

Each of the first nozzle and the second nozzle may be located on thecircumference of a concentric circle of the target rotor, and may bepositioned to face each of target points spaced apart from each other.

The first material and the second material may be sequentially injectedonto one target point of the target rotor when the target rotor rotatesaround the virtual rotation axis.

The first material may be high-temperature steam and the second materialmay be dry ice pellets.

The first soot blower may be disposed adjacent to the second outlet.

The heat exchanger cleaning system according to an embodiment of thepresent invention may further include a second soot blower positioned inan inner space of the first outlet.

The second soot blower may include a third nozzle through which thefirst material is injected toward the target rotor, and a fourth nozzlethrough which the second material is injected toward the target rotor.The fourth nozzle may be positioned at a predetermined interval from thethird nozzle.

A third distance of the third nozzle spaced apart from the virtualrotation axis of the target rotor may be substantially the same as afourth distance of the fourth nozzle spaced apart from the virtualrotation axis of the target rotor.

Each of the third nozzle and the fourth nozzle may be located on thecircumference of a concentric circle of the target rotor, and may bepositioned to face each of target points spaced apart from each other.

The second soot blower may be disposed adjacent to the second inlet.

The heat exchanger cleaning system according to an embodiment of thepresent invention may further include a driving unit for adjusting thepositions of the first soot blower and the second soot blower.

The driving unit may move the first soot blower and the second sootblower to move away from or closer to the virtual rotation axis of thetarget rotor. The driving unit may arrange the first soot blower suchthat the first distance and the second distance are substantially equalto each other by adjusting a spaced distance between the first andsecond nozzles. The driving unit may arrange the second soot blower suchthat the third distance and the fourth distance are substantially equalto each other by adjusting a spaced distance between the third andfourth nozzles.

While the target rotor is rotating, the first material and the secondmaterial may be continuously sprayed simultaneously.

A heat exchanger cleaning method using the above heat exchanger cleaningsystem according to an embodiment of the present invention may include:positioning the first soot blower in the inner space of the first inlet;injecting the first material through the first nozzle of the first sootblower and, simultaneously, injecting the second material through thesecond nozzle of the first soot blower toward the target rotor duringrotation of the target rotor; and removing foreign substances since thefirst material and the second material sequentially reach one point ofthe target rotor.

The first distance of the first nozzle spaced apart from the virtualrotation axis of the target rotor may be substantially the same as thesecond distance of the second nozzle spaced apart from the virtualrotation axis of the target rotor.

The first material may be high-temperature steam, and the secondmaterial may be dry ice pellets.

In the step of positioning the first soot blower, the first soot blowermay be disposed adjacent to the second outlet. Further, each of thefirst nozzle and the second nozzle may be positioned on thecircumference of a concentric circle of the target rotor, and may bepositioned to face each of target points that are spaced apart from eachother.

The heat exchanger cleaning method according to an embodiment of thepresent invention may further include: positioning a second soot blowerin an inner space of the first outlet; and injecting the first materialthrough the third nozzle of the second soot blower and, simultaneously,injecting the second material through the fourth nozzle of the secondsoot blower toward the target rotor during rotation of the target rotor.

In this regard, a third distance of the third nozzle spaced apart fromthe virtual rotation axis of the target rotor may be substantially thesame as a fourth distance of the fourth nozzle spaced apart from thevirtual rotation axis of the target rotor.

In the step of positioning the second soot blower, the second sootblower may be disposed adjacent to the second inlet. Further, each ofthe third nozzle and the fourth nozzle may be positioned on thecircumference of a concentric circle of the target rotor, and may bepositioned to face each of target points that are spaced apart from eachother.

The heat exchanger cleaning method according to an embodiment of thepresent invention may further include: adjusting the position of each ofthe first soot blower and the second soot blower by a driving unitconnected to the first soot blower and the second soot blower duringrotation of the target rotor.

In the step of adjusting the position of each of the first soot blowerand the second soot blower, each of the first soot blower and the secondsoot blower may move away from or closer to the virtual rotation axis ofthe target rotor. Further, a spaced distance between the first nozzleand the second nozzle of the first soot blower may be adjusted so thatthe first distance and the second distance are substantially equal toeach other. Further, a spaced distance between the third nozzle and thefourth nozzle of the second soot blower may be adjusted so that thethird distance and the fourth distance are substantially equal to eachother.

Advantageous Effects

The heat exchanger cleaning system and the heat exchanger cleaningmethod according to an embodiment of the present invention caneffectively remove foreign substances from the target rotor sincehigh-temperature steam and dry ice pellets are injected at the samepoint of the target rotor.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of a heat exchanger cleaning systemaccording to an embodiment of the present invention.

FIG. 2 is a perspective view of a part of the heat exchanger cleaningsystem according to an embodiment of the present invention.

FIG. 3 is a plan view of a part of the heat exchanger cleaning systemaccording to an embodiment of the present invention.

FIG. 4 is a bottom view of a part of the heat exchanger cleaning systemaccording to an embodiment of the present invention.

FIGS. 5 and 6 are perspective views of a part of the heat exchangercleaning system according to an embodiment of the present invention,respectively.

FIGS. 7 and 8 are plan views of a part of the heat exchanger cleaningsystem according to an embodiment of the present invention,respectively.

FIGS. 9 and 10 are bottom views of a part of the heat exchanger cleaningsystem according to an embodiment of the present invention,respectively.

EXAMPLES

The present invention may include various alterations and modifications,and specific embodiments will be illustrated in the drawings anddescribed in detail in the text. However, this is not intended to limitthe present invention to a specific form of disclosure. Instead, it isto be understood as including all changes, equivalents, and substitutesincluded in the spirit and scope of the present invention.

In the present application, terms such as “include” or “have” areintended to designate the presence of features, numbers, steps, actions,components, parts, or combinations thereof described in thespecification, but one or more other features. It is to be understoodthat possibility for the presence or addition of elements, numbers,steps, actions, components, parts or combinations thereof does notpreclude in advance. Further, if a component (or part) is said to be“above” (or “on”) another component (or part), this means not only thata component is “directly above” the other component (or part) but alsothat another component may be present therebetween. Likewise, if acomponent (or part) is said to be “below” (or “under”) another component(or part), this means not only that a component is “directly below” theother component (or part) but also that another component may be presenttherebetween. Further, the “above” (or “on”) and “below” (or “under”)refer to the position of a horizontal heat exchanger as viewed from theside (which may be referred to as the front side or the rear sidedepending on the point of view) (See FIG. 1 of the present application).Therefore, even if the heat exchanger could be inclined or placed upsidedown according to any use state of the heat exchanger, with regard tounderstanding the present invention, it is assumed that the heatexchanger is in the original horizontal state, and the position of eachcomponent (or part) must be identified.

In describing each drawing, similar reference numerals have been usedfor similar elements. Terms such as first and second may be used todescribe various elements, but elements should not be limited by suchterms. The terms are only used for the purpose of distinguishing onecomponent from another component. For example, without departing fromthe scope of the present invention, a first element may be referred toas a second element, and similarly, a second element may be referred toas a first element. Singular expressions include multiple expressionsunless the context clearly indicates otherwise.

Hereinafter, embodiments of the present invention will be described inmore detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a heat exchanger cleaning systemaccording to an embodiment of the present invention (may be referred toas a front view, a side view, or a rear view depending on the point ofview), and FIG. 2 is a perspective view of a part of the heat exchangercleaning system according to an embodiment of the present invention.

First, referring to FIGS. 1 and 2, the heat exchanger cleaning systemaccording to an embodiment of the present invention may include: atarget rotor 10; a first inlet 20 and a first outlet 23 through whichthe first gas G1 moves; a second inlet 30 and a second outlet 33 throughwhich the second gas G2 moves; a soot blower 100; and a driving unit 50.

The target rotor 10 may rotate around a virtual rotation axis 1extending in a first direction DR1. The target rotor 10 is a device formutually exchanging heat between high-temperature gas andlow-temperature gas that pass through the target rotor 10 while rotatingaround the virtual rotation axis 1. For example, the above device may bean air preheater or a gas preheater.

The target rotor 10 may include an outer frame 11, an inner frame 13,and a heat exchange plate 15.

The outer frame 11 may have a predetermined height extending in thefirst direction DR1, and may be an annular frame that cross the firstdirection DR1 and have an inner space corresponding to a plane formed ina second direction DR2 and a third direction DR3 crossing each other.

The inner frame 13 may be a frame that divides the inner space of theouter frame 11 in a radial direction and a circumferential direction.

The heat exchange plate 15 may be provided in an area partitioned by theouter frame 11 and the inner frame 13. The heat exchange plate 15 may bea lattice-shaped or corrugated metal plate.

The first inlet 20 may be positioned above the target rotor 10. Thefirst inlet 20 may be a passage through which the first gas G1 isintroduced toward the target rotor 10. Herein, the first inlet 20 may beconnected to a facility (not shown) such as a boiler, wherein the firstgas G1 may be a high temperature gas discharged from the inside of thefacility (not shown). For example, the first gas G1 may be substantiallyexhaust gas.

The first outlet 23 may be disposed under the target rotor 10. The firstoutlet 23 may be positioned opposite to the first inlet 20 with thetarget rotor 10 interposed therebetween. The first outlet 23 may be apassage through which the first gas G1 introduced through the firstinlet 20 passes through the target rotor 10 and then is discharged tothe outside. A temperature of the first gas G1 discharged through thefirst outlet 23 may be lower than a temperature of the first gas G1introduced through the first inlet 20.

The second inlet 30 may be disposed under the target rotor 10. Thesecond inlet 30 may be positioned to be spaced apart from the firstoutlet 23. The second inlet 30 may be a passage through which the secondgas G2 is introduced toward the target rotor 10. Herein, the second gasG2 is a gas having a temperature lower than that of the first gas G1,and may be, for example, air supplied from the outside.

The second outlet 33 may be disposed on top of the target rotor 10. Thesecond outlet 33 may be positioned to be spaced apart from the firstinlet 20. The second outlet 33 may be positioned to face the secondinlet 30 with the target rotor 10 interposed therebetween. The secondoutlet 33 may be a passage through which the second gas G2 introducedthrough the second inlet 30 passes through the target rotor 10 and thenis discharged. A temperature of the second gas G2 discharged through thesecond outlet 33 may be higher than a temperature of the second gas G2introduced through the second inlet 30. Further, the temperature of thesecond gas G2 discharged through the second outlet 33 may be lower thanthe temperature of the first gas G1 introduced through the first inlet20.

The second outlet 33 may be connected to a facility (not shown), and inthis case, the second gas G2 may be supplied into the facility (notshown).

The soot blower 100 may be a device for cleaning the target rotor 10 andmay be positioned in a region above and/or below the target rotor 10.

In an embodiment of the present invention, the soot blower 100 mayinclude a first soot blower 101 and a second soot blower 102.

The first soot blower 101 may be positioned in an area above the targetrotor 10 and may be disposed in an inner space of the first inlet 20.

The second soot blower 102 may be positioned in a region under thetarget rotor 10 and may be disposed in an inner space of the firstoutlet 23. Further, the second soot blower 102 may be positioned to facethe first soot blower 101.

The first soot blower 101 and the second soot blower 102 will bedescribed in more detail later.

The driving unit 50 may adjust the positions of the first soot blower101 and the second soot blower 102 together/simultaneously orrespectively. The driving unit 50 may adjust the positions of the firstsoot blower 101 and the second soot blower 102 to move away from orcloser to the virtual rotation axis 1. In this case, the first sootblower 101 and the second soot blower 101 may maintain a distance spacedapart from the target rotor 10 by a predetermined interval, while movingin a direction parallel to a plane formed by the second direction DR2and the third direction DR3.

FIG. 3 is a plan view of a part of the heat exchanger cleaning systemaccording to an embodiment of the present invention, and FIG. 4 is abottom view of a part of the heat exchanger cleaning system according toan embodiment of the present invention.

FIGS. 5 and 6 are perspective views of a part of the heat exchangercleaning system according to an embodiment of the present invention,respectively. Hereinafter, the first soot blower 101 and the second sootblower 102 will be described in detail with reference to FIGS. 3 to 6.

First, referring to FIGS. 3 and 5, the first soot blower 101 may bepositioned to overlap a first region R1 of the target rotor 10. At thistime, the first region R1 may be a region in which the first inlet 20 isdisposed on the target rotor 10. The first soot blower 101 may removeforeign substances on an upper portion of the target rotor 10 while thetarget rotor 10 rotates.

The first soot blower 101 may include a first supply unit 110 to supplya first material M1 and a second supply unit 120 to supply a secondmaterial M2. In one embodiment of the present invention, the firstmaterial M1 may be high-temperature steam, and the second material M2may be dry ice pellets.

The first supply unit 110 may include a first supply path 111 throughwhich the first material M1 moves and a first nozzle 113 through whichthe first material M1 is injected. The first nozzle 113 may bepositioned to be spaced apart from the virtual rotation axis 1 by afirst distance D1.

The second supply unit 120 may include a second supply path 121 throughwhich the second material M2 moves and a second nozzle 123 through whichthe second material M2 is injected. The second nozzle 123 may bepositioned at a predetermined interval from the first nozzle 113. Thesecond nozzle 123 may be positioned to be spaced apart from the virtualrotation axis 1 by a second distance D2.

In an embodiment of the present invention, the first nozzle 113 and thesecond nozzle 123 are located on a plane substantially parallel toanother plane formed by the second direction DR2 and the third directionDR3, respectively, the first distance D1 and the second distance D2 maybe substantially equal to each other. That is, the first nozzle 113 andthe second nozzle 123 are disposed on the circumference of a concentriccircle of the target rotor 10, respectively, and may be positioned toface each of target points spaced apart from each other.

While the target rotor 10 is rotating, the first material M1 and thesecond material M2 may be continuously injected simultaneously.Accordingly, on one concentric circle of the target rotor 10, the secondmaterial M2 can sequentially reach at a point where the first materialM1 was injected.

The first soot blower 101 may be disposed adjacent to a second region R2that is an area on the target rotor 10, in which the second outlet 33 isdisposed.

When the first gas G1 flows into the first inlet 20 in ahigh-temperature state, a temperature of an inner space of the firstinlet 20 can be maintained in a high-temperature state similar to thatof the first gas G1. When the first soot blower 101 injects the firstmaterial M1 and the second material M2 from the inner space of the firstinlet 20, it may be difficult for the first material M1 and the secondmaterial M2 to reach the target rotor 10 due to the temperature of theinner space of the first inlet 20. In particular, when the secondmaterial M2 is provided as dry ice pellets, the dry ice pellets may besublimated by the temperature of the inner space of the first inlet 20in a high temperature state.

Accordingly, the first soot blower 101 may be disposed in a place wherea temperature is relatively low even within the first region R1. Thatis, the first soot blower 101 is located as close to the second regionR2 as possible even within the first region R1, so that an amount ofsublimation of the dry ice pellets may be reduced as much as possible.

Referring to FIG. 3, it was illustrated and described that the firstsoot blower 101 is provided with a first supply unit 110 positionedcloser to the second region R2 than a second supply unit 120, but it isnot limited thereto. Alternatively, in the first soot blower 101, thesecond supply unit 120 may be located closer to the second region R2than the first supply unit 110.

Referring to FIG. 3, it was illustrated that the first supply unit 110and the second supply unit 120 are integrally formed in the first sootblower 101, but it is not limited thereto. The first supply unit 110 andthe second supply unit 120 may be separated from each other and may bespaced apart from each other at a predetermined interval.

Referring to FIG. 4, the second soot blower 102 may be positioned tooverlap a third region R3 of the target rotor 10. Herein, the thirdregion R3 may be a region in which the first outlet 23 is disposed underthe target rotor 10. The second soot blower 102 may remove foreignsubstances on a lower portion of the target rotor 10 while the targetrotor 10 rotates.

The second soot blower 102 may include a third supply unit 130 to supplythe first material M1 and a fourth supply unit 140 to supply the secondmaterial M2.

The third supply unit 130 may include a third supply path 131 throughwhich the first material M1 moves and a third nozzle 133 through whichthe first material M1 is injected. The third nozzle 133 may bepositioned to be spaced apart from the virtual rotation axis 1 by athird distance D3.

The fourth supply unit 140 may include a fourth supply path 141 throughwhich the second material M2 moves and a fourth nozzle 143 through whichthe second material M2 is injected. The fourth nozzle 143 may bepositioned at a predetermined interval from the third nozzle 133. Thefourth nozzle 143 may be positioned to be spaced apart from the virtualrotation shaft 1 by a fourth distance D4.

In an embodiment of the present invention, the third nozzle 133 and thefourth nozzle 143 are located on a plane substantially parallel toanother plane formed by the second direction DR2 and the third directionDR3, respectively, the third distance D3 and the fourth distance D4 maybe substantially equal to each other. That is, the third nozzle 133 andthe fourth nozzle 143 are respectively disposed on the circumference ofa concentric circle of the target rotor 10, and may be positioned toface each other and face target points located spaced apart from eachother

While the target rotor 10 is rotating, the first material M1 and thesecond material M2 may be continuously injected simultaneously.Accordingly, on one concentric circle of the target rotor 10, the secondmaterial M2 may sequentially reach a point where the first material M1was injected.

The second soot blower 102 may be positioned under the target rotor 10and adjacent to a fourth region R4, which is an area in which the secondinlet 30 is disposed.

A temperature of the first gas G1 discharged through the first outlet 23after passing through the target rotor 10 is lower than a temperature ofthe first gas G1 introduced through the first inlet 20, but may behigher than a temperature of the second gas G2 introduced through thesecond inlet 30.

Accordingly, the second soot blower 102 is positioned as close to thefourth region R4 as possible within the third region R3, whereby anamount of subliming the dry ice pellets as the second material M2 can bereduced as much as possible.

Further, the second soot blower 102 may inject a larger amount of thefirst material M1 and the second material M2 than the first soot blower101.

As the first material M1 and the second material M2 are injected in adirection opposite to the direction in which the first gas G1 isdischarged through the first outlet 23, it may be difficult for thefirst material M1 and the second material M2 injected from the secondblower 102 to reach the target rotor 10.

At this time, since the amount of the first material M1 and the secondmaterial M2 injected from the second soot blower 102 are increased, itis possible to easily remove the foreign substances on a lower portionof the target rotor 10.

Referring to FIG. 4, it was illustrated and described that the secondsoot blower 102 is provided with a third supply unit 130, and a fourthsupply unit 140 positioned closer to the fourth region R4 than the thirdsupply unit 130, but it is not limited thereto. Alternatively, in thesecond soot blower 120, the third supply unit 130 may be located closerto the fourth region R4 than the fourth supply unit 140.

Conventionally, the second soot blower 102 was positioned to overlap thefourth region R4. However, in this case, the first material and thesecond material M2 injected from the second soot blower 102 wereintroduced into the facility (not shown), hence causing a problem ofdeteriorating facility characteristics. On the other hand, in anembodiment of the present invention, the second soot blower 102 may bepositioned to overlap the third region R3, therefore, it is possible toprevent the first material M1 and the second material M2 injected fromthe second soot blower 102 from flowing into the facility (not shown).In other words, according to the present invention, for example, thesoot blower is not disposed in the second region R2 and the fourthregion R4 where air supplied from the outside is introduced into andthen pass through the regions.

Referring to FIG. 4, it was illustrated that the third supply unit 130and the fourth supply unit 140 are integrally formed in the second sootblower 102, but it is not limited thereto. The third supply unit 130 andthe fourth supply unit 140 may be separated from each other and may bepositioned at a predetermined interval.

Referring to FIGS. 5 and 6, the target rotor 10 may rotate in acounterclockwise direction around the virtual rotation axis 1 (see FIG.1). The first material M1 and the second material M2 may besimultaneously and continuously injected toward the target rotor 10while the target rotor 10 is rotating.

When the first material M1 and the second material M2 sequentially reachone point of the target rotor 10, foreign substances of the target rotor10 may be easily removed.

First, the first material M1 may reach a first point P1 of the targetrotor 10. As the target rotor 10 rotates in a counterclockwisedirection, the first point P1 migrates in the counterclockwisedirection. Further, when the first material M1 reaches a new secondpoint P2, the second material M2 may reach the first point P1.

Accordingly, it is possible to easily remove foreign substances from thefirst point P1 where the first material M1 and the second material M2sequentially reached.

FIGS. 7 and 8 are plan views of a part of the heat exchanger cleaningsystem according to an embodiment of the present invention,respectively. Hereinafter, with reference to FIGS. 7 and 8, it will bedescribed that the position of the first soot blower 101 is adjusted bythe driving unit 50.

Referring to FIGS. 1 and 7, the position of the first soot blower 101may be adjusted to move away from or closer to the virtual rotation axis1 by the driving unit 50. While adjusting the position of the first sootblower 101, the first distance D1 and the second distance D2 maymaintain substantially the same distance.

Referring to FIG. 8, a fifth distance D5, which is a spaced distancebetween the first nozzle 113 and the second nozzle 123 of the first sootblower 101, may be adjusted by the driving unit 50. The fifth distanceD5 may be shortened or extended according to a rotation speed of thetarget rotor 10.

FIGS. 9 and 10 are bottom views of a portion of the heat exchangercleaning system according to an embodiment of the present invention,respectively. Hereinafter, with reference to FIGS. 9 and 10, it will bedescribed that the position of the second soot blower 102 is adjusted bythe driving unit 50.

Referring to FIGS. 1 and 9, the position of the second soot blower 102may be adjusted to move away from or closer to the virtual rotation axis1 by the driving unit 50. While adjusting the position of the secondsoot blower 102, the third distance D3 and the fourth distance D4 maymaintain substantially the same distance.

Referring to FIG. 10, a sixth distance D6, which is a spaced distancebetween the third nozzle 133 and the fourth nozzle 143 of the secondsoot blower 102, may be adjusted by the driving unit 50. The sixthdistance D6 may be shortened or extended according to a rotation speedof the target rotor 10.

Hereinafter, a heat exchanger cleaning method for cleaning the targetrotor 10 using the heat exchanger cleaning system will be described. Forconvenience of explanation, a description that is duplicated with thedescription of the above-described heat exchanger cleaning system willbe omitted.

The heat exchanger cleaning method according to an embodiment of thepresent invention may include: positioning the first soot blower 101 inthe inner space of the first inlet 20; injecting the first material M1through the first nozzle 113 of the first soot blower 101 and,simultaneously, injecting the second material M2 through the secondnozzle 123 of the first soot blower 101 toward the target rotor duringrotation of the target rotor 10; and removing foreign substances sincethe first material M1 and the second material M2 sequentially reach onepoint of the target rotor 10.

In this regard, the first distance D1 of the first nozzle 113 spacedapart from the virtual rotation axis 1 of the target rotor 10 may besubstantially the same as the second distance D2 of the second nozzle123 spaced apart from the he virtual rotation axis 1 of the target rotor10.

The first material M1 may be high-temperature steam, and the secondmaterial M2 may be dry ice pellets.

In the step of positioning the first soot blower 101, the first sootblower 101 may be disposed adjacent to the second outlet 33 above thetarget rotor 10.

The first distance D1 of the first nozzle 113 spaced apart from thevirtual rotation axis 1 of the target rotor 10, may be substantially thesame as the second distance D2 of the second nozzle 123 spaced apartfrom the virtual rotation axis 1 of the target rotor 10.

The heat exchanger cleaning method according to an embodiment of thepresent invention may further include: positioning the second sootblower 102 in the inner space of the first outlet 23 under the targetrotor 10; and injecting the first material M1 through the third nozzle133 of the second soot blower 102 and, simultaneously, injecting thesecond material M2 through the fourth nozzle 143 of the second sootblower 102 toward the target rotor 10 during rotation of the targetrotor 10.

The third distance D3 of the third nozzle 133 spaced apart from thevirtual rotation axis 1 of the target rotor 10 may be substantially thesame as the fourth distance D4 of the fourth nozzle 143 spaced apartfrom the virtual rotation axis 1.

In the step of positioning the second soot blower 102, the second sootblower 102 may be disposed adjacent to the second inlet 30 under thetarget rotor 10.

The heat exchanger cleaning method according to an embodiment of thepresent invention may further include: adjusting the position of each ofthe first soot blower 101 and the second soot blower 102 by a drivingunit 50 connected to the first soot blower 101 and the second sootblower 102 during rotation of the target rotor 10.

Each of the first soot blower 101 and the second soot blower 102 maymove away from or closer to the virtual rotation axis 1 of the targetrotor 10. At this time, a spaced distance between the first nozzle 113and the second nozzle 123 of the first soot blower 101 may beappropriately adjusted such that the first distance D1 and the seconddistance D2 are substantially equal to each other, and similarly, aspaced distance between the third nozzle 133 and the fourth nozzle 143of the second soot blower 102 may be appropriately adjusted such thatthe third distance D3 and the fourth distance D4 are substantially equalto each other.

As such, although the above description was provided with reference tothe preferred embodiments of the present invention, it would beunderstood by those skilled in the art or those having ordinaryknowledge in the relevant technical field that various modifications andalterations of the present invention could be made within the scope ofthe present invention without departing from the spirit and scope of theinvention described in the appended claims later.

Therefore, the technical scope of the present invention should not belimited to the content described in the detailed description of thespecification, but should be determined only by the claims.

DESCRIPTION OF REFERENCE NUMERALS

10: target rotor 20: first inlet

23: first outlet 30: second inlet

33: second outlet 101: first soot blower

102: second soot blower 50: driving unit

113: first nozzle 123: second nozzle

133: third nozzle 143: fourth nozzle

M1: first material M2: second material

1. A heat exchanger cleaning system, comprising: a target rotor thatrotates around a virtual rotation axis extending in one direction; afirst inlet positioned above the target rotor, through which first gasis introduced toward target rotor; a first outlet positioned below thetarget rotor and opposed to the first inlet, through which first gaspassing through the target rotor is discharged; a second inletpositioned below the target rotor and spaced apart from the firstoutlet, through which second gas having a temperature lower than that ofthe first gas is introduced toward the target rotor; a second outletpositioned above the target rotor and opposed to the second inlet,through which the second gas passing through the target rotor isdischarged; and a first soot blower positioned in an inner space of thefirst inlet, wherein the first soot blower includes: a first nozzlethrough which a first material is injected toward the target rotor; anda second nozzle positioned at a predetermined interval from the firstnozzle, through which a second material is injected toward the targetrotor, and wherein a first distance of the first nozzle spaced apartfrom the virtual rotation axis of the target rotor is substantially thesame as a second distance of the second nozzle spaced apart from thevirtual rotation axis of the target rotor.
 2. The system according toclaim 1, wherein the first material and the second material aresequentially injected to one target point of the target rotor since thetarget rotor rotates around the virtual rotation axis.
 3. The systemaccording to claim 2, wherein the first material is high-temperaturesteam while the second material is dry ice pellets.
 4. The systemaccording to claim 1, wherein the first soot blower is disposed adjacentto the second outlet.
 5. The system according to claim 1, wherein thefirst nozzle and the second nozzle are respectively located on thecircumference of a concentric circle of the target rotor to face targetpoints, which are positioned to be spaced apart from each other.
 6. Thesystem according to claim 1, further comprising a second soot blowerpositioned in an inner space of the first outlet, wherein the secondsoot blower includes: a third nozzle through which the first material isinjected toward the target rotor; and a fourth nozzle positioned at apredetermined interval from the third nozzle, through which the secondmaterial is injected toward the target rotor, and wherein a thirddistance of the third nozzle spaced apart from the virtual rotation axisof the target rotor is substantially equal to a fourth distance of thefourth nozzle spaced apart from the virtual rotation axis of the targetrotor.
 7. The system according to claim 6, wherein the second sootblower is disposed adjacent to the second outlet.
 8. The systemaccording to claim 6, wherein the third nozzle and the fourth nozzle arerespectively located on the circumference of a concentric circle of thetarget rotor to face target points, which are positioned to be spacedapart from each other.
 9. The system according to claim 6, furthercomprising a driving unit to adjust the position of each of the firstsoot blower and the second soot blower, wherein the driving unit movesthe first soot blower and the second soot blower, respectively, awayfrom or closer to the virtual rotation axis of the target rotor, andwherein the first soot blower is disposed such that the first distanceand the second distance substantially become equal to each other byadjusting a spaced distance between the first nozzle and the secondnozzle, while the second soot blower is disposed such that the thirddistance and the fourth distance substantially become equal to eachother by adjusting a spaced distance between the third nozzle and thefourth nozzle.
 10. The system according to claim 1, wherein the firstmaterial and the second material are continuously injectedsimultaneously during rotation of the target rotor.
 11. A heat exchangercleaning method using a heat exchanger cleaning system, which includes:a target rotor that rotates around a virtual rotation axis extending inone direction; a first inlet positioned above the target rotor, throughwhich first gas is introduced toward the target rotor; a first outletpositioned below the target rotor and opposed to the first inlet,through which the first gas passing through the target rotor isdischarged; a second inlet positioned below the target rotor and spacedapart from the first outlet, through which second gas having atemperature lower than that of the first gas is introduced toward thetarget rotor; and a second outlet positioned above the target rotor andopposed to the second inlet, through which the second gas passingthrough the target rotor is discharged, the method comprising:positioning a first soot blower in an inner space of the first inlet;injecting a first material through the first nozzle of the first sootblower and, simultaneously, injecting a second material through thesecond nozzle of the first soot blower, which is positioned at apredetermined interval from the first nozzle, toward the target rotorduring rotation of the target rotor; and removing foreign substancessince the first material and the second material sequentially reach onepoint of the target rotor, wherein a first distance of the first nozzlespaced apart from the virtual rotation axis of the target rotor issubstantially the same as a second distance of the second nozzle spacedapart from the virtual rotation axis of the target rotor.
 12. The methodaccording to claim 11, wherein the first material is high-temperaturesteam, while the second material is dry ice pellets.
 13. The methodaccording to claim 11, wherein, in the first soot blower positioningstep, the first soot blower is disposed adjacent to the second outlet.14. The method according to claim 11, wherein, in the first soot blowerpositioning step, the first nozzle and the second nozzle arerespectively located on the circumference of a concentric circle of thetarget rotor to face target pointes, which are spaced apart from eachother.
 15. The method according to claim 11, further comprising:positioning a second soot blower in an inner space of the first outlet;and injecting the first material through a third nozzle of the secondsoot blower and, simultaneously, injecting the second material through afourth nozzle of the second soot blower, which is positioned at apredetermined interval from the third nozzle, toward the target rotorduring rotation of the target rotor, wherein a third distance of thethird nozzle spaced apart from the virtual rotation axis of the targetrotor is substantially the same as a fourth distance of the fourthnozzle spaced apart from the virtual rotation axis of the target rotor.16. The method according to claim 15, wherein, in the second soot blowerpositioning step, the second soot blower is disposed adjacent to thesecond inlet.
 17. The method according to claim 11, wherein, in thesecond soot blower positioning step, the third nozzle and the fourthnozzle are respectively located on the circumference of a concentriccircle of the target rotor to face target points, which are spaced apartfrom each other.
 18. The method according to claim 15, furthercomprising: adjusting the position of each of the first soot blower andthe second soot blower by a driving unit connected to the first sootblower and the second soot blower during rotation of the target rotor,wherein, in the step of adjusting the first soot blower and the secondsoot blower, the first soot blower and the second soot blower,respectively, move away from or closer to the virtual rotation axis ofthe target rotor, wherein a spaced distance between the first nozzle andthe second nozzle of the first soot blower is adjusted such that thefirst distance and the second distance are substantially equal to eachother, and wherein a spaced distance between the third nozzle and thefourth nozzle of the second soot blower is adjusted such that the thirddistance and the fourth distance are substantially equal to each other.